Reference is made to commonly-assigned copending U.S. patent application Ser. No. 10/022,230, filed Dec. 20, 2001, entitled: DRY INK REPLENISHMENT BOTTLE WITH INTERNAL PLUG AGITATION DEVICE, by Meetze, et al and U.S. patent application Ser. No. 10/022,229, filed Dec. 20, 2001, entitled: SELF-CLEANING MECHANISM ENABLING VISIBILITY INTO CONTAINERS OF PARTICLES, by Litwiller.
This invention relates to the packaging and subsequent removal of material that tends to clump or congeal when shipped or stored in containers. Many materials are packaged and shipped in particulate, pelletized, or granulated form, and some liquid/solid mixtures such as suspensions tend to form gels or to congeal into gelatinous clumps when shipped or stored. Unless special packaging arrangements are made, such liquid/solid mixtures and particulate or granulated matter typically settle and become more densely packed over time. A frequent consequence of such dense packing is often the formation of clumps when particles or liquid/solid mixtures are removed from their containers. For many products, such settling and clumping does not matter for the intended use. For other products, the particles, granules, and congealed material can be restored by agitating and/or aerating the particles or mixtures before the intended use. A common household example pertaining to particulate matter is the process of sifting flour before measuring and adding the flour to a batch for bread, cake, and similar baked items. Certain candies are also known to stick together in their containers during storage. Similarly, shaking of liquid/solid suspensions such as salad dressings restores the desired mixture composition. For some products, however, it is not practical or possible to perform such agitation and aerating from outside of the packaging in which the material has been stored or shipped. The present invention deals with a novel apparatus and method for providing in situ agitation and aeration within a container that is sealed before use. This apparatus and method obviates the need for human intervention such as shaking or tapping a container, thereby making the degree and type of agitation more reliable.
Although the handling and use of any number of particulate, granulated or pelletized products and liquid/solid mixtures may benefit from the present invention, the invention is described in relation to sealed containers that transport and load dry marking inks such as toner or a combination of toner and developer particles into printing machines such as electrophotographic copiers, printers, etc.
Generally, in the process of electrostatographic printing, a photoconductive insulating member is charged to a substantially uniform potential to sensitize the surface thereof. The charged portion of the photoconductive insulating layer is thereafter exposed to a light image of an original document to reproduced. This records an electrostatic latent image on the photoconductive member corresponding to the information areas contained within the original document. Alternatively, in a printing application, the electrostatic latent image may be created electronically by exposure of the charged photoconductive layer by an electronically controlled laser beam or light emitting diodes. After recording the electrostatic latent image on the photoconductive member, the latent image is developed by bringing a developer material charged of opposite polarity into contact therewith. In such processes the developer material may comprise a mixture of carrier particles and toner particles or toner particles alone (both these single component and dual component development systems shall hereinafter be called xe2x80x9ctonerxe2x80x9d). Toner particles are attracted to the electrostatic latent image to form a toner powder image that is subsequently transferred to copy sheet and thereafter permanently affixed to copy sheet by fusing.
In such a printing machines, the toner material is consumed in a development process and must be periodically replaced within the development system in order to sustain continuous operation of the machine. Various techniques have been used in the past to replenish the toner supply. Initially, new toner material was added directly from supply bottles or containers by pouring to the developer station located within the body of the automatic reproducing machine. The addition of such gross amounts of toner material altered the triboelectric relationship between the toner and the carrier in the developer station, thereby resulting in reduced charging efficiency of the individual toner particles and accordingly a reduction of the development efficiency when developing the electrostatographic latent image on the image bearing surface. In addition, the pouring process was both wasteful and dirty in that some of the toner particles became airborne and would tend to migrate into the surrounding area and other parts of the machine. Accordingly, separate toner hoppers with a dispensing mechanism for adding the toner from the hopper to the developer station in the printing machines on a regular or as needed basis have been provided. In addition, it has become common practice to provide replenishment toner supplies in a sealed container that, when placed in the printing machine, can be automatically opened to dispense toner into the toner hopper. In some of these designs, the toner cartridge may itself serve as the toner hopper. After this type of toner cartridge is mated to the printing machine at an appropriate receptacle, mechanisms are inserted into the toner cartridge that serve to transport the toner from the toner cartridge into the developer station or an intermediate toner hopper on a regulated basis. See, U.S. Pat. No. 5,903,806 issued to Matsunka et al.; U.S. Pat. No. 5,678,121 issued to Meetze et al.; and U.S. Pat. No. 5,495,323 issued to Meetze. In other designs, the toner cartridge is mated to the appropriate receptacle of the printing machine and then toner is dumped all at once from the toner cartridge into a toner hopper within the printing machine. Such toner in the hopper is then drawn into the developer station on a regulated basis. The toner cartridge, once its contents are dumped, is removed from the receiving receptacle and is either discarded or recycled.
In any design utilizing a customer replaceable toner cartridge for replenishment, one difficulty that arises is the uniform dispensing of the toner. In particular, toner particles are known to settle and clump during shipment and storage. This clumping phenomenon is caused for a variety of reasons: 1) particles of smaller size can fill and pack spaces between larger articles; 2) toner particles are often tacky; and 3) the electrostatic properties of toner particles enable charge attractions between particles. The result is often agglomerations, or clumps, of particles within the toner cartridge. These agglomerations often compact and form bridging structures within the toner cartridge, and such bridging structures adhere to the sides of the toner cartridges. Simple probes and augers as disclosed in patents such as U.S. Pat. No. 5,903,806 issued to Matsunka et al., U.S. Pat. No. 5,678,121 issued to Meetze et al., and U.S. Pat. No. 5,495,323 issued to Meetze may penetrate such agglomerations and bridging structures but do not break them up. Even rotation of the cartridges after mating onto a printing machine toner receptacle does not impart enough energy to shake the clumped toner particles apart from its various clumps and bridging structures. Since toner cost is a major component of the total cost of printing, any significant amount of toner left in a toner cartridge significantly increases the effective cost of using the printer. Worse, customers that do not receive the expected print volume from a cartridge may assume that the cartridge is faulty and make a warranty claim. In other cases, such customers have been known to make a service call that consumes valuable service and technician time.
In response to the above problems related to removal of substantially all toner from toner cartridges, various devices and procedures have been developed. One effective procedure when performed correctly is simply the shaking of a toner cartridge by human operators prior to mating the cartridge with the printing machine receptacle. However, many operators do not read the instructions and do not know or remember that toner cartridges need to be shaken. In addition, even when operators read instructions, humans inevitably interpret product instructions subjectively such that an instruction to xe2x80x9cvigorously agitatexe2x80x9d a cartridge may lead to too much force by a few operators and too little by others. The result is that some cartridges are shaken or pounded hard enough to be damaged while others are not shaken enough to break up clumps and bridges that may have formed. Once the cartridge is mated to the receiving receptacle while the toner particles remain clumped and bridged, the operator is left with several choices: One is to leave the cartridge as is and to risk wasting toner and/or believing that the printing system is consuming too much toner. A second choice is removal of the cartridge with its seals open, thereby risking contaminating the toner itself plus spilling the difficult-to-clean particles. A third choice is to try to strike, squeeze, or otherwise agitate the toner cartridge in situ. In addition to the probability that some toner nevertheless remains within the cartridge, such agitation in situ risks damage to the mating receptacle and associated parts of the printing machine. The end result is a frequent waste of valuable toner and a resulting increase in the costs of operating the printing machines plus the risk of warranty and service events.
Manufacturers of printing and other systems understand that human operators do not always follow instructions or perform the instructed activities correctly. In effect humans are inherently uncontrollable elements when asked to perform control processes. Accordingly, a number of automated solutions have been attempted. For toner cartridges that are mounted onto printing machines in order that toner be extracted in a regulated fashion, such cartridges are now often cylindrical in shape with spiral ribs located on the inside peripheral walls of the cartridges. An example of such prior art cartridges is shown in U.S. Pat. No. 5,495,323 issued to Meetze incorporated and is hereby incorporated by reference. See also, U.S. Pat. No. 5,903,806 issued to Matsuoka et al. and U.S. Pat. No. 5,576,816 issued to Staudt et al. that both disclose substantially cylindrical toner cartridges having on their peripheral surface a spiral groove. The toner cartridge and the receiving apparatus operate to rotate the cartridge and to thereby transport the toner within the spiral groove. The apparatus includes a supplying element in the form of an opening and a regulating device. Although toner cartridges with such spiral grooves are effective in urging toward the mouth of the cartridge, such grooves by themselves do little to break up the clumps or bridging described above. Even when the apparatus includes a probe, auger, or similar device that penetrates the stored toner in a cartridge, current designs place such probes only along the central axis of the cartridge. Toner clumped or agglomerated along the periphery of the toner cartridge may not be jostled or mixed by either the rotation of the cartridge or by the probe itself.
At least one prior art device employed a helical member such as a spring inside the toner cartridge for the express purpose of breaking up clumps, bridges, and other agglomerations. In U.S. Pat. No. 4,739,907, issued to Gallant, a cylindrical toner cartridge includes a dispensing opening at one end and an integral toner transport, mixing, and anti-bridging member rotatably supported within the container. The transport, mixing, and anti-bridging member comprises a first coiled spring element having a cross section substantially the same as the cross section of the cartridge and freely rotatable therein, which spring is wound in the direction to transport toner along its length toward the dispensing opening. The member also comprises a second coiled spring element having a cross section substantially smaller than the first spring element but being substantially concentrically positioned and being attached to the first spring element but wound in a direction opposite to the first spring element. In this manner, rotation of the cartridge while the spring members remain substantially fixed results in the scraping of clumped toner from the sides of the cartridge and mixing and penetration of any agglomerations and bridges within the interior of the cartridge by the inner spring.
One limitation to the above prior art cartridges and devices is that each is designed to work in or in conjunction with toner cartridges that rotate once mated to a toner receptacle on the printing machine. Without rotation of the cartridge, neither spiral grooves nor fixedly located springs actively engage toner particles within the cartridge. Additionally, recent advances in imaging and toner production has led to smaller toner particles that now may average less than 10 microns. In order to overcome electrostatic forces that tend to attract particles together, a substantial amount of aeration of the toner particles is preferred. It would be advantageous, therefore, to devise a toner cartridge assembly that both aerates toner and that automatically breaks up clumps and bridges within the toner even without rotating motion of the cartridge.
Although the above background for the present invention and several of its embodiments are explained in relation to toner cartridges, the present invention is believed to have wide applicability to any container of material, especially particulate matter prone to settle and clump and material prone to form gels or to congeal that nevertheless are easily removed once agitated.
Accordingly, one embodiment of the present invention is a mechanism for agitating material held in a container, comprising: (a) device that stores potential energy; (b) a lock-down mechanism that prevents release of energy from the spring member; (c) a releasing mechanism that, when engaged with the lock-down mechanism, prevents release of the potential energy from the spring member and, when disengaged from the lock-down mechanism, allows release of such potential energy from such spring member; and (d) an agitating member powered upon release of potential energy from the spring member, at least a portion of such agitating member being powered to move through the material held in the container.
A further embodiment of the present invention is a process for agitating material held in a container, comprising: (a) storing potential energy in a spring member; (b) engaging a releasing mechanism with a lock-down mechanism to prevent release of the potential energy stored in the spring member; (c) releasing the potential energy from the spring member upon disengagement of the releasing mechanism from the lock-down mechanism; and (d) agitating the material held in the container by an agitating member powered by the released potential energy.
A further embodiment of the present invention is a process for agitating marking materials materials in a cartridge, comprising: (a) storing potential energy in a spring member; (b) engaging a releasing mechanism with a lock-down mechanism to prevent release of the potential energy stored in the spring member (c) releasing the potential energy from the spring member upon disengagement of the releasing mechanism from the lock-down mechanism; and (d) agitating the toner materials held in the cartridge by an agitating member powered by the released potential energy.
Yet a further embodiment of the present invention is a cartridge for holding marking materials, comprising: (a) a device that stores potential energy; (b) a lock-down mechanism that prevents release of energy from the potential energy storage device; (c) a releasing mechanism that, when engaged with the lock-down mechanism, prevents release of the potential energy from the potential energy storage device and, when disengaged from the lock-down mechanism, allows release of such potential energy from such potential energy storage device; and (d) an agitating member powered upon release of potential energy from the potential energy storage device, at least a portion of such agitating member being powered to move through the toner material held in the cartridge.